/*

 * jcinit.c

 *

 * Copyright (C) 1991-1995, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 *

 * This file contains initialization logic for the JPEG compressor.

 * This routine is in charge of selecting the modules to be executed and

 * making an initialization call to each one.

 *

 * Logically, this code belongs in jcmaster.c.  It's split out because

 * linking this routine implies linking the entire compression library.

 * For a transcoding-only application, we want to be able to use jcmaster.c

 * without linking in the whole library.

 */



#define JPEG_INTERNALS

#include "jinclude.h"

#include "jpeglib.h"





/*

 * Master selection of compression modules.

 * This is done once at the start of processing an image.  We determine

 * which modules will be used and give them appropriate initialization calls.

 */



GLOBAL void

jinit_compress_master (j_compress_ptr cinfo)

{

  /* Initialize master control (includes parameter checking/processing) */

  jinit_c_master_control(cinfo, FALSE /* full compression */);



  /* Preprocessing */

  if (! cinfo->raw_data_in) {

    jinit_color_converter(cinfo);

    jinit_downsampler(cinfo);

    jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);

  }

  /* Forward DCT */

  jinit_forward_dct(cinfo);

  /* Entropy encoding: either Huffman or arithmetic coding. */

  if (cinfo->arith_code) {

    ERREXIT(cinfo, JERR_ARITH_NOTIMPL);

  } else {

    if (cinfo->progressive_mode) {

#ifdef C_PROGRESSIVE_SUPPORTED

      jinit_phuff_encoder(cinfo);

#else

      ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

    } else

      jinit_huff_encoder(cinfo);

  }



  /* Need a full-image coefficient buffer in any multi-pass mode. */

  jinit_c_coef_controller(cinfo,

			  (cinfo->num_scans > 1 || cinfo->optimize_coding));

  jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);



  jinit_marker_writer(cinfo);



  /* We can now tell the memory manager to allocate virtual arrays. */

  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);



  /* Write the datastream header (SOI) immediately.

   * Frame and scan headers are postponed till later.

   * This lets application insert special markers after the SOI.

   */

  (*cinfo->marker->write_file_header) (cinfo);

}

